Different types of acids from fermentation environment or industrial microorganisms exist during fermentation process. Acids may inhibit growth and metabolism of industrial strains, namely acid stress. The tolerance mechanisms of acid stress include regulation of intracellular proton concentration, protection and restoration of intracellular macromolecules, changes in cell membrane composition and acid stress response at whole cell level. Screening and modification methods have been applied to improve acid-stress tolerance of industrial strains for decades. In this review, we provide insights into acid-stress tolerance of industrial microorganisms and address the modification of microbial pathways to improve acid-stress tolerance.
Acids ; chemistry ; Fermentation ; Hydrogen-Ion Concentration ; Industrial Microbiology ; Metabolic Engineering

BACKGROUNDHemodynamic evaluation is crucial for the management of patients with pulmonary hypertention. Clinicians often prefer a rapid and non-invasive method. This study aimed to examine the feasibility of transthoracic echocardiography for the measurements of hemodynamic parameters in patients with pulmonary hypertension.

METHODSA prospective single-center study was conducted among 42 patients with pulmonary hypertension caused by different diseases. Transthoracic echocardiography and right-heart catheterization were performed within 24 hours. Pulmonary artery systolic, diastolic and mean pressure (PASP, PADP and PAMP), cardiac output (CO), and pulmonary capillary wedge pressure (PCWP) were measured by both methods. A linear correlation and a Bland-Altman analysis were performed to compare the two groups of hemodynamic parameters.

RESULTSA good correlation was found between invasive and non-invasive measurements for PASP (r = 0.96), PADP (r = 0.85), PAMP (r = 0.88), CO (r = 0.82), and PCWP (r = 0.81). Further agreement analysis done by the Bland-Altman method showed that bias and a 95% confidence interval for PASP, PADP, and CO were clinically acceptable while great discrepancies existed for PAMP and PCWP.

CONCLUSIONSThe non-invasive measurements by PASP, PADP, and CO in patients with pulmonary hypertension correlate well with the invasive determinations. Transthoracic echocardiography (TTE) was inappropriate for estimating PCWP and PAMP.

Adolescent ; Adult ; Cardiac Catheterization ; Cardiac Output ; Echocardiography ; Female ; Hemodynamics ; Humans ; Hypertension, Pulmonary ; physiopathology ; Male ; Middle Aged ; Prospective Studies ; Pulmonary Wedge Pressure

OBJECTIVETo investigate the associations between periodontal diseases, presence of Porphyromonas gingivalis (P. gingivalis), serum levels of pro-inflammatory mediators and preterm low birth weight (PLBW).

METHODS60 women (30 PLBW and 30 healthy women), were recruited after postpartum within 3 days in this case-control study. Periodontal measurements including plaque index (PI), bleeding index (BI), probing pocket depth (PD) and clinical attachment loss (CAL) were assessed. The subgingival plaque was collected before periodontal examination and analysed by polymerase chain reaction (PCR) for the presence of the 16S rRNA gene specific to P. gingivalis, while the venous and umbilical cord blood specimens collected were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTSThe PLBW cases had a poorer oral conditions and the presence of P. gingivalis was found in a higher proportion in the PLBW than the healthy pregnant (56.7% vs. 30.0%, P < 0.05). Both of the presence of periodontitis and P. gingivalis have been found to be associated weakly with a shorter gestational age and a lower birth weight (P < 0.05). The levels of IL-1beta, IL-6 and prostaglandin-E2 (PGE2) in both of the blood samples showed higer levels between the PLBW and normal groups (P < 0.01). The IL-1beta and PGE2 levels in maternal serum were higher with a severe periodontal disease in the PLBW group (P < 0.01).

CONCLUSIONThere may be a possible link between periodontal diseases and PLBW.

Adult ; Case-Control Studies ; Dental Plaque ; Dental Plaque Index ; Female ; Humans ; Infant, Low Birth Weight ; Infant, Newborn ; Interleukin-6 ; Periodontal Diseases ; Periodontitis ; Porphyromonas gingivalis ; Pregnancy ; Premature Birth ; RNA, Ribosomal, 16S

OBJECTIVETo investigate the modification of GSTM1, GSTT1 and GSTP1 gene polymorphisms on urinary 1-hydroxypyrene (1-OHP) excretions in workers under different exposure levels.

METHODSFour hundred and forty-seven occupationally exposed workers from two coking plants and 220 control workers from a wire rod plant were genotyped to analyze the modification of GSTM1, GSTT1 and GSTP1 gene polymorphisms on urinary 1-OHP excretions.

RESULTSThe urinary 1-OHP concentration in exposed group was much higher than that in control group (4.61 vs 0.34 µmol/mol Cr, P < 0.05). Occupational exposure levels and cigarette smoking were of the dominating factors affecting 1-OHP excretions in urine. After controlling potential confounders, decreased excretion of urinary 1-OHP was associated with GSTP1 I105V AG + GG genotype in coke oven workers (single-gene model, P = 0.012; multi-gene model, P = 0.011) and with GSTT1 null type in the analysis including all subjects (P = 0.055 in both single-gene and multi-gene models). GSTT1 and GSTP1 were interacted on the urinary concentrations of 1-OHP.

CONCLUSIONUrinary 1-OHP concentrations can be modified by GSTM1, GSTT1 and GSTP1 gene polymorphisms, indicating that these genes are involved in the metabolism of polycyclic aromatic hydrocarbons.

Adolescent ; Adult ; Control Groups ; Genotype ; Glutathione S-Transferase pi ; genetics ; Glutathione Transferase ; genetics ; Humans ; Male ; Middle Aged ; Occupational Exposure ; Polymorphism, Single Nucleotide ; Pyrenes ; analysis ; Urinalysis ; Young Adult

BACKGROUNDAn implantable cardioverter-defibrillator (ICD) has been suggested for heart failure patients for primary prevention of sudden cardiac death. However, few data have been reported on the application of ICD as primary prevention of sudden cardiac death in China. We evaluated the value of primary prevention ICD therapy in Chinese patients with heart failure.

METHODSThirty-four patients at an average age of (60.2 +/- 13.7) years seen in Peking Union Medical College Hospital were treated with ICD implantation for primary prevention of sudden cardiac death from November 2005 to July 2009. Single-chamber ICDs were implanted in 16 (47.0%) cases, and dual-chamber or cardiac resynchronization therapy defibrillators in 18 (53.0%) cases. The patients had an average left ventricular ejection fraction of (26.9 +/- 5.5)% (11% to 35%), of which 18 (53.0%) patients had ischemic cardiomyopathy and 16 (47.0%) patients had non-ischemic cardiomyopathy. All patients were followed up at three months after the implantation and every six months thereafter or when prompted by an ICD event.

RESULTSThere were five (14.7%) deaths, including two of heart failure and three with a non-cardiac course, during an average follow-up of (15.0 +/- 11.9) months. Forty-one ICD therapy events were recorded, including 19 (46.3%) appropriate ICD therapies in six patients and 22 (53.7%) inappropriate ICD therapies in four patients with single chamber leads. Inappropriate ICD therapies were mainly due to supraventricular tachyarrhythmias, especially atrial fibrillation. Patients with ischemic cardiomyopathy and non-ischemic cardiomyopathy did not differ in the incidence of either appropriate or inappropriate therapy.

CONCLUSIONSICD for primary prevention of sudden cardiac death in China prevents patients from arrhythmia death. Relatively high incidence of inappropriate therapies highlights the importance of an atrial lead.

Aged ; Death, Sudden, Cardiac ; prevention & control ; Defibrillators, Implantable ; adverse effects ; Female ; Heart Failure ; mortality ; therapy ; Humans ; Male ; Middle Aged ; Treatment Outcome

OBJECTIVETo study the characteristics of occupational exposure of polycyclic aromatic hydrocarbons (PAHs) in coke oven workers.

METHODSSamples were collected individually and PAHs concentration in the ambient air were assayed by high performance liquid chromatography (HPLC) and toxic equivalency factors (TEFs) were introduced to assess the carcinogenic potency.

RESULTSThe levels of PAHs occupational exposure in oven workers at topside was higher than at side oven and bottom oven (P < 0.05). Non-carcinogenic PAHs were more than 70% of total PAHs and benzo[a]pyrene accounted for 65.5% approximately 72.4% of total benzo[a]pyrene equivalents. Total occupational exposure level of PAHs in coke oven workers was positively related to the content of benzo[a]pyrene and pyrene, respectively (r(2) = 0.84, r(2) = 0.94, P < 0.05).

CONCLUSIONCoke oven workers were exposed to a high level of PAHs which possessed some extent of carcinogenic potency, and benzo[a]pyrene is the chief carcinogenic substance.

Benzo(a)pyrene ; analysis ; toxicity ; Carcinogens ; analysis ; toxicity ; Chromatography, High Pressure Liquid ; Coke ; Humans ; Occupational Exposure ; Polycyclic Compounds ; analysis ; toxicity

OBJECTIVETo observe the clinical features and cardiac magnetic resonance imaging (CMR) characteristics of patients with endomyocardial biopsy (EMB)-proven cardiac amyloidosis (CA).

METHODSEMB proven CA patients underwent CMR examination from September 2006 to December 2010 were included. The findings of clinical manifestation, electrocardiogram, echocardiography and CMR were analyzed.

RESULTSAmong the 18 patients with EMB verified CA, 5 patients underwent CMR. All 5 patients had heart failure symptoms and electrocardiogram was abnormal. Echocardiogram showed concentric left ventricular hypertrophy, granular appearance of the myocardium, left atrial enlargement and moderate to severe left ventricular diastolic dysfunction. CMR revealed increased thickness of the left ventricular wall (especially at the inter-ventricular septum), enlarged bilateral auricle, restricted left ventricular filling with normal or mild to moderate reduced systolic function. Pleural and pericardial effusions were observed in 2 patients. Abnormal late gadolinium enhancement (LGE) was detected in all 5 patients. CMR revealed different patterns of LGE. Left ventricular global subendocardial delayed gadolinium enhancement or transmural delayed gadolinium enhancement were found, and patients also showed line-, granular- or patchy-like enhancement. The degree and range of LGE paralleled the disease course and were consistent with electrocardiogram changes.

CONCLUSIONSAs a noninvasive diagnostic tool, CMR is valuable in the diagnosis of CA. For patients with clinical suspicion of CA, CMR could be a helpful diagnostic tool, especially in the hospitals where EMB is not available.

Amyloidosis ; diagnosis ; Biopsy ; Cardiomyopathies ; diagnosis ; Echocardiography ; Electrocardiography ; Gadolinium ; Gadolinium DTPA ; Humans ; Hypertrophy, Left Ventricular ; Magnetic Resonance Imaging ; Myocardium ; Systole

Objective To investigate the clinical manifestations, diagnosis and treatment of primary intracranial tumors of multiple cellular origins. Methods The clinical data including the clinical manifestations, imaging findings, and treatment of 8 patients with primary intracranial tumors of multiple cellular origins were retrospectively analyzed, and the possible mechanism of these tumors were explored. Results A total of 16 primary intraeranial tumors were found in the 8 patients, including intraeranial meningioma (8 tumors), pituitary adenoma (3 tumors), schwannoma (2 tumors), and glioma (2 tumors). The tumors were resected in a single operation in 5 cases, and in two surgical sessions in 3 cases. Twelve tumors were radically resected, 3 were subtotally resected, and 1 was partially resected. Conclusion MR is an important diagnostic modality for primary intraeranial tumors of multiple cellular origins. Tumor resection in one or staged operations combined with radiotherapy or chemotherapy is the primary treatment option for these tumors.

OBJECTIVETo observe the optimal timing of operation and the therapeutic effect of endoscopic optic nerve decompression for traumatic optic neuropathy (TON).

METHODSThe clinical records of 90 consecutive patients with TON (93 eyes) after head and/or maxillofacial trauma from April 1998 to March 2007 were reviewed and analyzed. All patients were either unresponsive or intolerant to medication before they underwent intranasal endoscopic optic nerve decompression. The time interval between the injury and operation ranged from one day to 97 days (median 5.5 days). Among the 93 eyes, there were 71 eyes with no visual acuity before operation and 22 eyes with residue visual acuity, including light perception in 1 eye, hand movement in 5 eyes, counting fingers in 13 eyes, 0.04 in 1 eye, and 0.1 in 2 eyes. Duration of follow-up ranged from 6 days to two years (median 8 days).

RESULTSAfter decompression, 35 patients (36/93 eyes, 38.7%) showed improvement of visual acuity, 53 patients (55 eyes, 59.1%) remained the same as before operation, while 2 patients (2 eyes, 2.2%) showed decreased visual acuity. Among patients with visual acuity beyond light perception before decompression, 68.2% of them (15/22 eyes) experienced visual improvement, whereas only 22.9% (8/35 eyes, 0.02 in two eyes) among patients who lost visual acuity immediately after injury, and 36.1% (13/36 eyes, 0.02 in five eyes) among those who lost visual acuity gradually after injury. There was a significant difference in visual improvement between group with visual acuity and group with no visual acuity (chi(2) = 11.864, P < 0.01). Among patients with no visual acuity, 41.2% of those (7/17 eyes) who underwent operation within 3 days of injury, experienced improvement in visual acuity, compared with 25.9% (14/54 eyes) for those who underwent the operation more than 3 days after injury. It was indicated that no significant difference in visual improvement between these two groups (chi(2) = 1.46, P > 0.05). When comparing different sites of fracture, the effect of surgery was the most desirable (55.6%, 10/18 eyes improved) if the fracture occurred simultaneously in both exterior and interior walls of optic canal, followed by the interior wall fracture (45.7%, 21/46 eyes). The operation was less effective if there was no fraction (20%, 4/20 eyes) or if the fracture occurred in exterior wall alone (11.1%, 1/9 eyes).

CONCLUSIONSEndoscopic optic nerve decompression is a minimally invasive procedure with no adverse cosmetic effects. Early operation is recommended for saving vision, even though visual acuity is lost immediately after injury. However, the satisfactory clinical effects of endoscopic optic nerve decompression require further study.

Adolescent ; Adult ; Child ; Decompression, Surgical ; methods ; Endoscopy ; Female ; Humans ; Male ; Middle Aged ; Neurosurgical Procedures ; Nose ; surgery ; Optic Nerve Injuries ; surgery ; Treatment Outcome ; Young Adult

OBJECTIVETo summarize the electrocardiography and echocardiography features of patients with cardiac amyloidosis (CA) diagnosed by endo-myocardial biopsy (EMB).

METHODSA total of 20 consecutive patients [7 men, mean age (50 ± 12) years] referred for EMB because of clinical suspicion of CA from September 2006 to October 2009 were included in the study. Primary CA was diagnosed in 11 out of 20 patients (55%) by EMB and biomarkers examination. The electrocardiography and echocardiography features were analyzed.

RESULTSThe voltage of all the limb leads were low in the 11 CA patients [mean values of (0.33 - 0.51) mV], the incidence of low voltage and pseudo-infarction patterns were 45% and 45%, respectively. Concentric hypertrophy and normal left ventricular diameters were evidenced in all CA patients on echocardiography, left atrial enlargement (n = 10, 91%), granular/sparking appearance of the myocardium (n = 9, 82%) and moderate to large pericardial effusion (n = 7, 64%) as well as left ventricular systolic dysfunction (n = 8, 73%) were often presented in CA patients.

CONCLUSIONSThe diagnosis of primary CA should be considered in patients with unknown origin of heart failure, concentric hypertrophy and normal left ventricular diameters with granular/sparking appearance of the myocardium or pericardial effusion presented on echocardiography and low voltage of limb leads or pseudo-infarction pattern presented on electrocardiography. EMB and serum (urine) biomarkers examinations should be then performed to confirm or exclude the diagnosis of CA.

Adult ; Amyloidosis ; diagnostic imaging ; physiopathology ; Cardiomyopathies ; diagnostic imaging ; physiopathology ; Echocardiography ; Electrocardiography ; Female ; Humans ; Immunoglobulin Light-chain Amyloidosis ; Male ; Middle Aged ; Retrospective Studies